Blood glucose monitoring is a way of testing the concentration of glucose in the blood (glycemia). Particularly important in the care of diabetes mellitus, a blood glucose test is performed by piercing the skin (typically, on the finger) to draw blood, then applying the blood to a chemically active disposable ‘test-strip’. The test is usually referred to as capillary blood glucose. Current teaching counsels diabetic patients to measure their blood glucose level from two to seven times a day depending on the nature and severity of their individual cases. Based on the observed pattern in the measured glucose levels, the patient and physician together make adjustments in diet, exercise and insulin intake to better manage the disease. This information should be available to the patient immediately.
A biosensor is a sensor which utilizes the molecule identifying abilities of biological materials such as microorganisms, enzymes, and antibodies to apply the biological materials as molecule recognition elements. To be specific, the biosensor utilizes a reaction which occurs when an immobilized biological material recognizes a target specific component, such as oxygen consumption by respiration of a micro-organism, an enzyme reaction, or luminescence. Among biosensors, enzyme sensors have been advanced in practical applications, and for example, enzyme sensors for glucose reduces an electron acceptor by an electron generated by a reaction between an enzyme and a substrate included in a sample solution as a specimen, and a measurement device electrochemically measures the oxidation-reduction quantity of the electron acceptor, thereby to perform quantitative analysis of the specimen. The first electrochemical glucose biosensor relied on a thin layer of glucose oxidase (GOx) entrapped over an oxygen electrode via a semipermeable dialysis membrane. Measurements were made based on the monitoring of the oxygen consumed by the enzyme-catalyzed reaction (Wang 2008). Second and third generation biosensors also rely on the effects of enzyme-catalyzed reactions to determine glucose levels (Ferri et al. 2011).